Hello. Giraffes with longer necks survive compared to those with shorter necks because of natural selection. Over time, natural selection favors the traits that would make a species thrive better in the environment. Giraffes with short necks won't have access to that much food compared to those with long necks thus they eventually died out.
The answer is An object is in motion if it changes position relative to a reference point. You assume that the reference point is stationary, or not moving.
